William Henry BarlowFRSFRSEFICEMIMechE (10 May 1812 – 12 November 1902) was an English civil engineer of the 19th century, particularly associated with railway engineering projects. Barlow was involved in many engineering enterprises. He was engineer for the Midland Railway on its London extension and designed the company's London terminus at St Pancras.

Barlow married Selina Crawford Caffin in May 1842 at Charlton, Kent.[2] The couple had four sons and two daughters. Their son Crawford Barlow became a civil engineer and was in practice with his father.[1]

From 1832 he spent six years working as an engineer in Constantinople, Turkey, helping build an ordnance factory on behalf of machine tool manufacturers Maudslay, Sons & Field. He also produced a report for the Turkish government on lighthouses in the Bosphorus, which led to his first two scientific papers.[1][note 1] For his services to the Turkish government he was awarded the Order of Nishan Iftikhar (Order of Glory).[1]

Whilst working on the Midland Railway's main line, Barlow established that the replacement of sleepers was a larger part of the cost of track maintenance than the replacement of rails because the sleepers decayed more quickly than the rails wore-out and needed renewal more often.[3] To remove the cost of providing and replacing sleepers, he developed and patented his own rail design in 1849. It had a wide flanged profile which could be laid directly on to track ballast without the need for sleepers, with just periodic tie-bars to maintain the correct gauge.[note 2] Known as the Barlow rail, it was widely used, especially by the Great Western Railway.[1]

In 1857, Barlow left the Midland Railway to form his own consultant engineering practice in London, with the Midland Railway as a significant client.[1] Following the death of Isambard Kingdom Brunel in 1859, Barlow was commissioned with John Hawkshaw to complete the Clifton Suspension Bridge, Bristol, construction of which had been stalled since 1843 due to insufficient funds to finish it. Reusing the chains from Brunel's earlier Hungerford Suspension Bridge in London, demolished in 1860, Barlow and Hawkshaw completed the bridge in 1864 with a more robust deck than Brunel had planned and other variations caused by the reuse of the existing chains.[4] Its 702-foot (214 m) span was the longest in Britain at the time.[1]

Between 1862 and 1869, Barlow was consultant engineer for the Midland Railway's southern extension from Bedford to London, including the layout of the London terminus station at St Pancras on Euston Road. To deal with the sloping site and the need to cross the Regent's Canal a short distance to the north, the platforms were constructed on a raised structure supported on cast iron columns and girders. Under this storage was laid out for beer from the breweries at Burton upon Trent.[5] With assistance from Rowland Mason Ordish,[6] Barlow also designed the arched, cast iron station canopy which spans 240 feet (73 m) across the platforms without intermediate support – then the widest of its kind in the world. It was designed as a cost effective and efficient means of avoiding the need for additional solid structure in the lower level.[7]George Gilbert Scott designed the hotel in front of the train shed.[6]

On 28 December 1879, the central section of the North British Railway's bridge across the River Tay near Dundee collapsed in the Tay Bridge disaster as an express train crossed it in a heavy storm. All 75 passengers and crew on the train were killed. As the newly elected President of the Institution of Civil Engineers,[note 3] Barlow was appointed as a member of the Board of Trade's Court of Inquiry into the disaster. He sat with Henry Cadogan Rothery and William Yolland, co-authoring one of the final reports with Yolland recommending a commission be established to examine wind loads on bridges. In its report dated 30 June 1880, the Court of Inquiry concluded that the bridge, designed by Sir Thomas Bouch and opened only the year before its collapse, had been "badly designed, badly built and badly maintained".[9] The entire central box truss section of the bridge known as the "High Girders" collapsed along with the thirteen trestles supporting it, leaving a gap of nearly half-a-mile in the 2-mile-long (3.2 km) bridge.

In 1881 Barlow sat as member of the Wind Pressure (Railway Structures) Commission established at the recommendation of the Tay Bridge report.[10] He led the design of the replacement Tay Bridge (1882–87) with his son Crawford Barlow as engineer.[1] The new design used large monocoque piers to support a double railway track. The old brick and masonry piers from the first bridge were retained as breakwaters for the new piers upstream. They can still be seen today as a forlorn reminder of the tragedy of 1879.

Barlow was an early experimenter with civil engineering uses for steel, carrying out research at Woolwich Arsenal in the 1850s and being a member of the Institution of Civil Engineers' committee on the subject. From 1873 he was a member of a Board of Trade committee which produced the first recommendations on safe working loads for steel in railway structures in 1877.[1]

Barlow also experimented with sound recording. In February 1874 he presented the Royal Society with a talk On the Pneumatic Action which accompanies the Articulation of Sounds by the Human Voice, as exhibited by a Recording Instrument.[11] He called his 'recording instrument' a Logograph.[12][13]

With his health failing, he retired from practice in 1896, along with his son. He died on 12 November 1902 from exhaustion after breaking his leg,[1] and was buried in Charlton Cemetery in a plot adjacent to that of his father's grave. His home "High Combe", Charlton Road, Greenwich, is marked with a blue plaque.[15]

^Barlow's first papers were Experiments made at Constantinople on Drummond's light (1836) and The adaptation of different modes of illuminating lighthouses as depending on their situations and the object contemplated in their erection (1837).[1]